Generally, electronic appliances, such as portable terminals, notebooks, portable multimedia players (PMPs), digital cameras, digital camcorders and the like, are provided with a chargeable and dischargeable battery pack such that they can be used while being carried.
The battery pack is provided therein with a temperature sensor device in order to protect batteries by detecting the temperature thereof when lithium ion cells are discharged.
FIG. 1 is a view showing a conventional sensor device, and FIG. 2 is a perspective view showing the improved conventional device of FIG. 1.
As shown in FIGS. 1 and 2, the conventional sensor device is configured such that a sensor element 10 is fixed between lead frames 11 and is covered with an insulating film to insulate the sensor element 10 from the lead frames 11.
However, the conventional sensor device is problematic in that it is not sufficiently protected from external shocks such as impact, compression and the like, which may break the sensor element 10. Particularly, when the sensor device is mounted on a battery cell of a notebook and then the battery cell is pressed by a plastic pack, there is a problem in that the sensor device is damaged by shocks.
Therefore, as shown in FIG. 2, the invention provides a support 230 in order to protect the sensor element 210. However, there is also a problem in that shocks are transferred to the sensor element 210 when the support 230 is thin, and the upper and lower films are spaced apart from each other around the support 230 when the support 230 is thick, so that liquid is introduced into the gap therebetween, with the result that the sensor element becomes damaged.
Particularly, such a problem has a great influence on reliability especially in terms of voltage characteristics.